JPH07176259A - Neutral device for circuit breaker - Google Patents

Abstract

PURPOSE:To improve contact reliability by dividing a current in fixed and movable contactors into two parts, so as to weaken electromagentic repulsive force of each contractor. CONSTITUTION:A neutral movable contactor 92 is formed almost in a U shape by one piece 92A coming into contact with and separating from the first neutral fixed contactor 90, the other piece 92B coming into contact with and separating from the second neutral fixed contractor 91 and a connecting piece 92C for connecting these one piece 92A and the other piece 92B. When a neutral handle 94, in a condition that it is brought into contact with a point end of the other piece 92B of the contactor 92, is operated to turn in a base end direction of the other piece 92B, a point end of the one piece 92A of the movable contractor 92 is rotated in the same direction to a direction of rotating the handle 94 with the base end of the other piece 92B serving as the center, to separate from the fixed contactor 90. Accordingly, after the handle 94 is brought into contact with a point end of the other piece 92B of the contractor 92, small force for turning is only required to improved operability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker neutral device for electrically opening and closing a grounding side wire of a circuit breaker.

[0002]

2. Description of the Related Art Generally, when power is supplied from a power supply to a load, the power is supplied to a main breaker in a distribution board, and then the branch breaker is branched from the main breaker before being supplied to a load.

That is, the connection bar on the power supply side of the main breaker is connected to the input terminal of each branch breaker, and the connection bar on the ground side of the main breaker is connected to the neutral switch arranged in the distribution board to connect the branch breaker. Connect the power supply side wire from the output terminal of to the load and the ground side wire from the neutral switch to the load.

However, in this case, the power supply side line leading to the load is led from the output terminal of the branch breaker, and the ground side line is led from the neutral switch provided at a position distant from the branch breaker, so that it is led to the load side. It is necessary to change the lengths of the pair of electric wires of the power supply side wire and the grounding side wire and to connect them by arranging them inside the distribution board, which deteriorates the wiring workability.

Therefore, the applicant has proposed a circuit breaker equipped with a neutral device (Japanese Patent Application No. 5-271).
685). The neutral device of this circuit breaker is 2
One fixed contactor, one movable contactor formed in a substantially U-shape that comes in contact with and separated from these fixed contactors, and a contact spring that urges the movable contactor in the direction of contacting each fixed contactor. And an operation handle for moving the movable contact to and from the fixed contact.

The fixed contactor comprises a first fixed contactor connected to the ground side input terminal and a second fixed contactor connected to the ground side output terminal.
And a fixed contact, which are arranged in parallel. In the movable contact, one fixed contact is brought into contact with and separated from the inner surface of the tip of one piece, and the other fixed contact is brought into contact with and separated from the outer surface of the base end of the other piece facing this one piece, and the connecting piece has a substantially U-shape. Is formed in. The contact spring is formed of a coil spring and contacts one outer surface of one of the movable contacts to bias the movable contacts in a direction of contacting each fixed contact. By rotating the operation handle, the other end of the movable contact is brought into contact with the movable contact in the proximal direction to separate the movable contact from the fixed contacts.

The neutral device of this circuit breaker rotates the operating handle in the ON state where the movable contacts are in contact with the respective fixed contacts (the movable contacts are urged by the fixed springs by the contact springs). When operated dynamically, the operation handle comes into contact with the other end of the movable contact in the direction of the proximal end from the outer surface of the other end of the movable contact to oppose the spring force of the contact spring and separate the movable contact from each fixed contact. .

[0008]

In the neutral device for the circuit breaker described above, however, one fixed contactor is brought into contact with or separated from the inner surface of the tip of the other piece by using one member as the movable contactor. At the same time, since the other fixed contact is brought into contact with and separated from the outer surface of the base end of the other opposite to this one, and the connecting piece is formed into a substantially U-shape, electromagnetic repulsion due to current flowing through the movable contact and the fixed contact There is a problem in that the force is large and thus the contact reliability is reduced.

The present invention has been made in view of such circumstances, and its object is to weaken the electromagnetic repulsive force of each contact by dividing the current flowing through the fixed contact and the movable contact. Accordingly, it is an object of the present invention to provide a neutral device for a circuit breaker that improves contact reliability.

[0010]

In order to solve such a problem, a neutral device for a circuit breaker according to the present invention has two fixed contacts arranged side by side and one fixed contact on the inner surface of the distal end of the one piece. The two fixed contacts, which are brought into contact with and separated from each other, are attached to and separated from the base end outer surface of the other piece, and the two movable contacts are formed in a substantially U-shape by the connecting pieces, and the two movable contacts. A single contact spring for urging the child from one piece toward the other piece, and a single operation handle for abutting against the tips of the other two pieces of the two movable contacts to bring them into and out of contact with the respective fixed contacts. It is provided as a configuration.

[0011]

According to the structure of the present invention, the current flowing from one fixed contact is divided into two movable contacts and flows into the other fixed contact.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the circuit breaker shown in FIGS. The housing 1 of this circuit breaker is made of an insulating material such as synthetic resin, equipped with power supply side connection terminals 2 and 3 and ground side connection terminals 4 and 5 on both sides, and will be described later in approximately the center outside the top surface. It has a rectangular handle protrusion 6 for projecting the power supply side handle, and attachment parts 7, 7 for fixing to the distribution board on both sides near the bottom surface, which are fixed to the distribution board. By mounting a fixing member (not shown), the bottom surface (mounting surface) is fixed in contact with the distribution board. The handle protrusion 6 has a rectangular window hole 9 into which a power supply side handle to be described later is inserted,
The outside has a large diameter and the inside has a small diameter through hole 2
Two operating holes 10 and 11 are provided. As shown in FIG. 4, the housing 1 includes a body 12 having side openings for laterally fitting components, a first cover 13 for closing the front opening of the body 12, and a rear opening of the body 12. Second cover
It consists of 14 and.

The interior of the body 12 has a partition wall 12h at the center.
Firstly, a link mechanism 15 for shutting off the electric path by means of an electric arc and an arc extinguishing chamber (arc extinguishing member) 16 for separating and cooling the arc are provided.
It is divided into a section 12A and a second section 12B in which a leakage detection device 17 for detecting a leakage current and a test button 18 are arranged. In the first section 12A, a concave terminal groove 12a for mounting the ground side connecting terminal 4 and a concave terminal groove 12b for mounting the power supply side connecting terminal 2 of the electric path on the lower rear side of the terminal groove 12a.
And the arc extinguishing chamber (arc extinguishing member) below the terminal groove 12b.
And an exhaust port 12c for exhausting the gas generated inside 16. Further, an insulating plate 19 for partitioning the power source side and ground side connecting terminals 2 and 4 and a bimetal described later is arranged on the inner side of the terminal groove 12a. Further, a fitting portion 20 for fitting and fixing an arc traveling plate, which will be described later, is provided under the arc extinguishing chamber (arc extinguishing member) 16. Also, the first section 12A
A ground side connection conductor accommodating portion 21 in which a ground side connection conductor to be described later is arranged is formed near the bottom surface (mounting surface) of the.

In the second section 12B, a concave terminal groove 12d for mounting the power supply side connecting terminal 3 and a concave terminal groove for mounting the ground side connecting terminal 5 on the upper rear side of the terminal groove 12d. It has 12e. Further, cut grooves 12f, 12g to which a leakage detecting substrate to be described later is mounted are formed inside the upper surface and the lower surface of the second section 12B. Furthermore, the partition wall
A hook shaft 22 for hooking a tension spring described later is formed on the side surface of 12h. On the upper part of the partition wall 12h, an earth leakage display device 23 for displaying the earth leakage state is arranged.

The first cover 13 closes the front opening of the body 12, and the body 12 in the state where the opening of the body 12 is closed.
Link mechanism 15, arc extinguishing chamber 16 (arc extinguishing device), earth leakage detection device 17, test button 18, earth leakage display device 23 arranged inside 12
And so on. The second cover 14 closes the back opening of the body 12, and holds the neutral device 24, the ground side connecting conductor 24a, etc., which are arranged in the body 12 with the opening of the body 12 closed. is there.

The link mechanism 15 is composed of an opening / closing mechanism section for manually opening and closing the electric path, and an abnormal current detecting section for opening the electric path when an abnormal current flows. The opening / closing mechanism is a power source side movable contactor whose middle portion is pivotally supported by a frame described later.
25, an opening spring 26 for urging the power supply side movable contact 25 in the opening direction, a connection link 27 having one end connected to the power supply side movable contact 25, and a shaft supported together with the power supply side handle 28 on the frame. A latch link 30 having a slit 30a that swingably supports a movable shaft 29 held at the other end of the connecting link 27, a trip link 31 that is axially supported by a frame and latches the latch link 30, and one end is movable. A handle link 33 connected to the connecting link 27 via the shaft 29 and the other end connected to the power supply side handle 28 via the movable shaft 32, and a latch link to the frame.
A power source side handle 28 held together with 30, a frame 34 holding these members, and a power source side contact 35 interposed between the power source side connection terminals 2 and 3 are provided.

The movable contact 25 on the power source side has a frame at the middle portion.
An elliptical slit 25a is provided so as to be axially supported by 34, and a pair of parallel leg pieces and a connecting piece that connects the leg pieces are formed into a substantially U shape, and a movable contact 25b is provided at one end of the connecting piece.
And a protrusion for locking one end of the opening spring 26 at the other end of the connecting piece. In addition, a daruma hole (not shown) for inserting a movable iron core, which will be described later, forcibly opening the movable contact 25 on the power source side in the opening direction is formed in substantially the center of the connecting piece. This power supply side movable contact
25 is electrically connected to frame 34 via copper stranded wire 36. The opening spring 26 is formed in a coil shape, one end of which is hooked on the projection of the power supply side movable contactor 25 and the other end of which is hooked on a second yoke which will be described later, to open the power supply side movable contactor 25 in the opening direction. Is urged to.

The connecting link 27 is composed of a pair of parallel leg pieces having axial holes at both ends, and a connecting piece for connecting the leg pieces from the vicinity of the axial hole at one end of the leg piece. The movable link 37 is connected to the power source side movable contact 25, and the other end is connected to the latch link 30 and the handle link 33 via the movable shaft 29. The latch link 30 has a shaft hole axially supported by the frame 34, and has a movable shaft 29.
It has a slit 30a for swingably supporting, and is composed of a pair of leg pieces that are formed in a generally V shape in a side view and are parallel to each other, and a connecting piece that connects the leg pieces. That is, the connecting link 27 and the handle link 33 are swingably held in the slit 30a via the movable shaft 29.

The trip link 31 is composed of a standing piece and a side piece integrally connected at an intermediate portion of the standing piece. An ear piece is formed on the side opposite to the side piece, and the side piece and the ear piece are formed. The frame 34 is axially supported through the bearing holes. Also, this trip link
An engaging portion for engaging the connecting piece of the latch link 30 is formed at the tip of the side piece 31. Further, there is provided a torsion coil spring 38 which is fitted and supported by the frame 34 and which is locked to a side piece and a first yoke described later and biases the side piece toward the connecting piece side of the latch link 30. At the upper end of the standing piece, there are provided a bimetal interlocking part that interlocks with the deformation of the bimetal 39, and a projecting piece that is provided in a direction intersecting with the bimetal interlocking part and to which an opening of a first lever described later is mounted. At the lower end of the standing piece, there is provided a movable iron core interlocking plate which is interlocked with the movement of the movable iron core described later.

The handle link 33 is composed of a pair of leg pieces having shaft holes at both ends and parallel to each other, and a connecting piece for connecting the leg pieces from the center of the leg pieces.
It is connected to the connection link 27 via 29, and is connected to the power supply side handle 28 via the movable shaft 32 to the shaft hole at the other end. The power supply side handle 28 is made of an insulating material such as a synthetic resin, and swings the operation part projected from the handle projection 6 on the upper surface of the housing 1 and the window hole 9 of the housing 1, and is viewed from the side. A base portion serving as a center of rotation having a fan-shaped swinging portion, a shaft hole for holding the latch link 30 in the frame 34, and a spring shaft hole into which one end of a spring described later is inserted. ,,. Further, at one end of the swinging portion, a protrusion having a shaft hole to which the handle link 33 is connected via the movable shaft 32 is provided.

The frame 34 is composed of a frame main body integrally provided with the first yoke 40, and a frame cover connected to the frame main body via three fixed shafts 41, 42, 43. The frame body is formed into a substantially triangular shape with an opening inside when viewed from the side, and has a shaft hole into which the fixed shafts 41, 42, and 43 are inserted at the apex and the two bottom sides, respectively. The first yoke 40 is integrally provided in the. Like the frame body, the frame cover is formed into a substantially triangular shape with an opening inside when viewed from the side, and has a shaft hole into which the fixed shafts 41, 42, and 43 are inserted at both the apex and the bottom end, respectively. is doing. Further, from one end of the bottom side, a leg piece extending downward and a side piece extending from the tip of the leg piece toward the frame main body are connected. One of the copper stranded wires 36 is welded to this frame cover, and the other of the copper stranded wires 36 is welded to the power supply side movable contact 25, whereby the frame 34 and the power supply side movable contact 25 are electrically connected. .

The power supply side contact 35 is composed of a movable contact 25b fixed to the power supply side movable contact 25 and a fixed contact fixed to the connecting member 44.
44a and is interposed between the power supply side connection terminals 2 and 3. The movable contact 25b is provided at one end of the connecting piece of the power source side movable contact 25 as described above. Fixed contact 44a
Is provided at one end of the connecting member 44.

The connecting member 44 is formed in a substantially L shape from a connecting member main body 45 connected to the power source side connecting terminal 3 and a fixed contact portion 46 hanging from the connecting member main body 45. The connection member main body 45 has one end connected to the power supply side connection terminal 3 and is equipped with an insulating material such as vinyl in the center and inserted into a zero-phase current transformer described later, and the other end is held by the partition wall 12h. . Fixed contact part 46
Has a fixed contact 44a, and is arranged with the fixed contact 44a fitted in a fitting hole formed in an arc traveling plate described later. Even if the fixed contact 44a melts due to the heat of the arc generated when the contact 35 on the power supply side is forcibly opened due to an abnormal current, it is prevented from leaking to the outside from the fitting hole, and is reused even after the forced contact is opened due to the abnormal current It is easy to do.

The abnormal current detector comprises a bimetal 39 for detecting an overcurrent and a detection electromagnet 47 for detecting a short circuit current. Bimetal 39 has 2 different thermal expansion coefficients.
It is made by superposing a plurality of thin plates together, and the whole is bent and formed into a substantially L shape from a vertical piece and a horizontal piece, and heat is generated and deformed in accordance with the applied current. A screw hole into which a gap adjusting screw is screwed is provided at the upper end of the vertical piece. This bimetal 39
The power supply side connection terminal is welded to the frame
2 Placed near. The detection electromagnet 47 includes a first yoke 40 provided integrally with the frame 34, a fixed iron core 48 provided on the first yoke 40, a trip link drive rod 49 penetrating the fixed iron core 48, and a movable iron core 50. A return spring 51 for urging the power source side movable contactor 25 side, a movable iron core 50 forcibly opening the power source side movable contactor 25, a coil tube 52 covering these, and a coil winding the coil tube 52. 53 and a second yoke 54 connected to the first yoke 40. 1st York
The upper piece 40 and the lower piece, which are opposed to each other, are formed into a substantially U shape through a connecting piece, and the upper piece is integrally provided on the frame 34. The fixed iron core 48 has a through hole, and its tip is the first.
It is fitted from the inside into a fitting hole formed in the connecting piece of the yoke 40 and fixed by caulking.

The trip link drive rod 49 is formed in a cylindrical shape which is longer than the fixed iron core 48, and is inserted into the through hole of the fixed iron core 48 so as to be swingable. The return spring 51 is formed in a coil shape and is compressed and installed between the fixed iron core 48 and the movable iron core 50.
The movable iron core 50 is biased toward the movable contact 25 on the power supply side. The movable iron core 50 is slidably fitted in the coil tube 52,
The forced opening rod projecting from one end of the coil barrel 52 projects outward from the small diameter portion of the coil cylinder 52, and a flange is formed at the tip of the rod, which penetrates the dulled hole of the power supply side movable contact 25. The coil tube 52 is
It has a through hole and is composed of a large diameter portion and a small diameter portion, and this small diameter portion is fitted from the inside into a fitting hole of the second yoke 54 described later. The coil 53 is wound around the coil tube 52, and one end of the coil 53 is folded back in the axial direction and welded to a power source side terminal plate described later. Further, one end of the copper stranded wire 36 is welded to the other end of the coil 53, and the copper stranded wire 36 is attached to the vertical piece of the bimetal 39.
The other end is electrically connected to the bimetal 39 by welding. The second yoke 54 is composed of a lower piece and a side piece continuous with the lower piece, and has a fitting hole into which the small diameter portion of the coil tube 52 is fitted. Further, a locking portion for locking the opening spring 51 to urge the power source side movable contact 25 in the opening direction is provided at the tip of this side piece.

The arc extinguishing chamber 16 (arc extinguishing device) has an arc traveling plate 55 for moving the arc generated at the time of short circuit interruption from the power source side contact 35 composed of the movable contact 25b and the fixed contact 44a, and the body 12 The divided and cooled gas is exhausted from the exhaust port 12c of the. The arc traveling plate 55 is formed in a substantially L shape by a vertical piece and a horizontal piece, and the horizontal piece is provided in the fitting portion 20 above the ground-side connection conductor accommodating portion 21 near the bottom (mounting surface) of the body 12. The mated vertical pieces are arranged in parallel with the grounding side connecting conductor 24a in a state where they are fitted to the partition wall 12h.
The magnetic field due to the current flowing in 5) is on the ground side (ground side connection conductor 2
It is less susceptible to the magnetic field due to the current flowing in 4a). Therefore, the arc generated when the abnormal current flows and the movable contact 25b is forcibly opened from the fixed contact 44a can be easily extended by the arc traveling plate 55, so that the adverse effect of the ground side connecting conductor 24a can be reduced. As shown in FIG. 1, the vertical piece has a fitting hole 55a formed at the center for fitting the fixed contact 44a therein. For example, an abnormal current such as a ground fault current or a short circuit current causes the movable contact 25b to move. Even if the fixed contact 44a is melted by the heat of the arc generated when the contact is forcibly opened, the fitting hole
It becomes difficult to flow from 55a, and it can be reused even after forced opening. Further, a protruding rib 55b is provided on the center line of the horizontal piece of the arc traveling plate 55 so that the arc traveling is facilitated and clogging is avoided.

Next, the operating principle of the link mechanism 15 will be described with reference to FIGS. 3, 8 and 9. That is, when the power supply side handle 28 is tilted from the OFF state side shown in FIG. 3 toward the ON state side shown in FIG. 8, the latch link 30 is tripped.
While being latched by 31, the movable shaft 29 moves in the slit 30a of the latch link 30 from the upper side to the lower side, and the movable shaft 29 moves the connecting link 27. Then, when the movable shaft 29 moves beyond the straight line connecting the movable shaft 29 and the fixed shaft 42, the movable shaft 29 is rapidly inverted, and the power supply side movable contact 25 connected to the connection link 27 is centered on the fixed shaft 41. As a result of rotation, the movable contact 25b comes into contact with the fixed contact 44a as shown in FIG. At this time, the fixed shaft 41 is positioned in the middle of the elliptical slit 25a provided in the middle portion of the power source side movable contact 25, and the movable contact
Applying contact pressure to 25b. Further, in the overcurrent trip in the trip state, when an overcurrent flows in the electric path in the ON state shown in FIG. 3, the self-heat generation of the bimetal 39 gradually pushes the trip link 31 so that the connecting piece of the latch link 30 is engaged. When the latch link 30 is rotated by the opening spring 26 by being released from the stopper, the power source side movable contact 25 is rotated around the fixed shaft 41 in the direction away from the fixed contact 44a. Then, as shown in FIG. 9, the power source side contact 35 is opened. In the short circuit trip, when a short circuit current flows in the electric path in the ON state shown in FIG. 3, the movable iron core 50 of the detection electromagnet 47 is attracted to the fixed iron core 48. As a result, the trip link drive rod 49 is pushed out and pushes the movable iron core interlocking plate of the trip link 31, and the trip link 31 rotates so that the latch link 30 is released, and as described above, the power source side movable contact 25 is opened. Operate. However, before the power-side movable contact 25 is opened by such link interlocking, that is, at the same time as the operation of the movable iron core 50, the flange portion of the movable iron core 50 is locked to the power-side movable contact 25, and The movable contact 25b is pulled away from the fixed contact 44a. That is, just before the latch link 30 is tripped, the movable contact 25 on the power supply side rotates in the direction of compressing the opening spring 26 with the fixed shaft 41 as a fulcrum to perform the opening operation.

As shown in FIG. 10, the leakage detecting device 17 is
A zero-phase current transformer 56 that detects an unbalanced current in the electric path, and a control circuit unit (not shown) that amplifies the output of the zero-phase current transformer 56,
The movable contact plate 57 that holds the test button 18 so as to project from the housing 1, and the unbalanced current flowing in the zero-phase current transformer 56 via the test circuit unit (not shown) by contacting the movable contact plate 57. It is composed of a fixed contact shaft 58 for generating a leak current and a leakage detection substrate 59 to which these components are attached. This leakage detection substrate 59 is arranged in the vicinity of the ground side connection terminal 5.

The ground-side connection conductor 24 is provided on the leakage detection substrate 59.
It forms a slit through which a can pass. The upper end of this leakage detection board 59 is the cut groove 12f of the body 12, and the lower end is the body.
The electric leakage detection device 17 is provided in the housing 1 by mounting it in the 12 cut grooves 12g. Further, the control circuit unit is a switching element composed of an amplifier that outputs a signal to the output when the unbalanced current flowing in the electric circuit exceeds the sensitivity current, and a thyristor that turns on when the signal output from the amplifier is output. It consists of and.

The test button 18 is actually operated from the upper surface of the housing 1, and is composed of a substantially cylindrical operation portion and a leg portion extending from the lower surface of the operation portion.
Operation hole 11 so that the operation part projects above the top of the housing 1.
Be attached to. Further, the tip end of the leg portion is provided with a notch in the center so as to have elasticity, and has an abutting portion which is locked inside the operation hole 11 when inserted into the operation hole 11 and abuts on the movable contact plate 57. It is provided. By pressing the test button 18, the movable contact plate 57 abuts the fixed contact shaft 58, and an unbalanced current is generated in the zero-phase current transformer 56 via the test circuit section. The test circuit section includes a current limiting resistor that limits a current and a test winding.

The earth leakage display device 23 has a housing when an earth leakage occurs.
1 and a spring 61 for projecting the leakage display member 60 from the operation hole 10 of the housing 1.
And the first and second transmission levers 62 and 63 that rotate the trip link 31 to trip the opening / closing mechanism portion, and the tension spring 64 that pulls the second transmission lever 63 toward the lower surface of the body 12.
And an electromagnet device 65 for rotating the second transmission lever 63 by the current amplified by the control circuit section of the leakage detection device 17. The earth leakage indicator member 60 has a cylindrical shape and is a display portion that protrudes from the operation hole 10 of the housing 1 when electric leakage occurs, and has a substantially prismatic shape that can move forward and backward in the operation hole 10. One end of the spring 61 is inserted. Cut groove and first transmission lever
And a leg portion having a locked piece that is locked to 62. The spring 61 is formed in a coil shape, and is inserted into the fixed shaft 42 and has one end inserted into the spring shaft hole of the power supply side handle 28 and the other end inserted into the cut groove of the leakage display member 60. It is attached so as to urge. Further, at the other end, there is an abutting part which comes into contact with the other end of the swinging part of the power source side handle 28 when the power source side handle 28 is in the neutral position and the power source side handle 28 is moved to the opening position. is doing. The first transmission lever 62 is composed of a vertical piece having an opening and an engagement piece that is provided continuously with the vertical piece and that has an engagement portion that engages with the engagement portion of the second transmission lever 63. Composed. In addition, the fixed shaft of the frame 34 is provided between the vertical piece and the engaging piece.
The insertion recess into which the 43 is inserted is provided, and by inserting the fixed shaft 43 into the insertion recess and the projection of the trip link 31 into the opening, the first transmission lever 62 is set to the frame.
Held rotatably on 34.

The second transmission lever 63 is provided with a diagonal piece having a locking portion for locking the locked portion of the earth leakage indicating member 60 at the tip, and the first transmission lever 62 connected to the diagonal piece. An engaging piece having an engaging portion that engages with the engaging portion, and an engaging piece that is continuously provided below the locking portion of the oblique piece and that is provided in a direction that intersects the oblique piece. The hooking shaft is hooked to the portion, and the hooking piece is connected to the side surface of the diagonal piece and has a locking piece that locks the movable core of the electromagnet device 65 described later. The fixed shaft 41 of the frame 34 is provided between the inclined pieces and the engaging pieces in series.
Is provided with an insertion recess into which the second transmission lever 63 is rotatably held by the frame 34 by mounting the fixed shaft 41 in the insertion recess. According to the present embodiment, the transmission lever that transmits the output of the leakage detection device to the cutoff mechanism is composed of two members, but any number of members can be applied.

The tension spring 64 is formed in a coil shape and has a second
Is hooked on the hook shaft of the transmission lever 63 and the hook shaft 22 of the body 12. The electromagnet device 65 includes a coil bobbin 66 around which a coil is wound, a fixed iron core 67, a movable iron core 68, and a yoke 69.
It consists of and. The coil terminals at both ends of the coil bobbin 66 are connected to the control circuit unit and the test circuit unit of the leakage detection device 17 via lead wires (not shown). Fixed iron core
67 is a coil bobbin formed in a substantially cylindrical shape and having a kerf.
It is inserted into the through hole and is held by the yoke 69. The movable iron core 68 includes a movable iron core body having a cylindrical shape, a continuous shaft continuously provided to the movable iron core body, and a locked portion that is locked to a locking piece of the second transmission lever 63. Since the movable iron core body is constructed and inserted into the through hole formed in the coil bobbin 66 and the movable iron core body is prevented from coming off by the holding recess of the yoke 69, the movable iron core 68 does not fall from the coil bobbin 66. yoke
The upper piece 69 and the lower piece 69 facing each other are formed in a substantially U-shape via a connecting piece, and the upper piece and the lower piece are fitted into the flange portion of the coil bobbin 66 in a concavo-convex manner, so that the coil bobbin 66 It is installed. Further, the upper piece and the lower piece are provided with holding recesses for holding the cut groove of the fixed iron core 67 and the movable iron core body so as not to come off from the through hole.

In this circuit breaker, when an unbalanced current flows in the electric path, it is detected by the zero-phase current transformer 56 to generate a secondary output, which is amplified by an amplifier to turn on the switching element and the coil is excited to electromagnet. The movable iron core 68 of the device 65 is attracted to the fixed iron core 67 side, and the movable iron core 68 pushes up the second transmission lever 63, whereby the second transmission lever 63 rotates about the fixed shaft 41, and the second transmission lever 63 rotates. 63 is the first transmission lever 62
Is pushed down, the first transmission lever 62 rotates about the fixed shaft 41, and the trip link 31 inserted in the first transmission lever 62 rotates about the fixed shaft 43. After this,
A movable contact similar to the trip operation of the link mechanism 15 described above.
Remove 25b from fixed contact 44a to open contact 35 on the power supply side. Further, when the second transmission lever 63 rotates, the leakage indicator member 60 projects from the operation hole 10 of the housing 1 and the power supply side handle 28 is held at the neutral position. Furthermore, when conducting a leakage test, the test button 18 is pressed to bring the movable contact plate 57 into contact with the fixed contact shaft 58, and a signal is applied to the test circuit section, so that an unbalanced current flows in the zero-phase current transformer 56. It is generated and the electromagnet device 65 works to attract the movable iron core 68. Therefore, as described above, by the link mechanism 15,
Remove movable contact 25b from fixed contact 44a.

Further, when the leakage indicator member 60 projects from the operation hole 10 of the housing 1 due to the leakage and the power source side handle 28 is in the neutral position, the power source side handle 28 is displaced toward the opening position, The other end of the swinging portion of the handle 28 abuts on an abutting portion 61a formed on the spring 61, and the other end 61b of the spring 61 moves downward in FIG. As a result, the leakage display member 60, into which the other end 61b of the spring 61 is inserted, is displaced toward the inside of the housing 1, and this displacement locks the leakage display member 60 to the second transmission lever 63. According to the present embodiment, when the leakage display member projects from the operation hole of the housing and the power supply side handle is in the neutral position, the power supply side handle is moved toward the opening position to move the leakage display member to the second position. Although it is locked to the transmission lever of
The one in which the leakage indicator member is locked to the second transmission lever by moving the power supply side handle toward the closed position is also applicable.

Terminals are power supply side connection terminals 2 and 3 (input / output terminals)
And ground side connection terminals 4 and 5. The power supply side wire connection terminal 2 is a terminal screw that has a driver operation hole.
70, a terminal plate 71 having a screw hole 71a into which the terminal screw 70 is screwed and a projecting piece 71b connected to the coil 53 of the detection electromagnet 47, and a nut 72 with which the terminal screw 70 is screwed,
And is disposed in the terminal groove 12b of the first section 12A. Like the power supply side connection terminal 2, the power supply side connection terminal 3 has a terminal screw 73 having a driver operation hole and a mountain-shaped metal plate, and a screw hole 74a with which the terminal screw 73 is screwed, and a connecting member. The second partition is composed of a terminal plate 74 that is connected to the base plate 44 and a nut 75 to which the terminal screw 73 is screwed.
It is arranged in the terminal groove 12d of 12B.

The ground side connection terminal 4 has a terminal screw 76 having a driver operation hole, a screw hole 77a into which the terminal screw 76 is screwed, and a projection 77b to which the ground side connection conductor 24a is welded. The terminal plate 77 and the nut 78 with which the terminal screw 76 is screwed together are arranged in the terminal groove 12a of the first section 12A. The ground-side connection terminal 5 has a terminal screw 79 having a driver operation hole and a mountain-shaped metal plate, a screw hole 80a into which the terminal screw 79 is screwed, and a fixed contact described later. The terminal block 80 and the nut 81 with which the terminal screw 79 is screwed, and the second section
It is arranged in the terminal groove 12e of 12B.

As shown in FIG. 11, the neutral device 24 includes a first neutral fixed contactor 90 (fixed contactor) connected to the ground-side connection terminal 5 at one end, and the first neutral fixed contactor 90. The second neutral fixed contacts 91 (fixed contacts) arranged side by side, and the two neutral movable contacts 9 that come in contact with and separate from the respective neutral fixed contacts 90, 91.
2,92 (moving contact) and neutral moving contact 92,92
Contact spring 93 that urges the neutral fixed contacts 90, 91 toward the neutral fixed contacts 90, 91, and the neutral handle 94 (operation that moves the neutral movable contacts 92, 92 toward and away from the neutral fixed contacts 90, 91 against the spring bias). Handle) and a grounding side connecting conductor 24a which is welded to another fixed contactor 91 and to the grounding side connecting terminal 4 at the other end.

The first neutral fixed contacts 90 are continuously arranged so as to project from the terminal plate 80 of the ground side connection terminal 5 at one end. As shown in FIG. 11, the second neutral fixed contactor 91 is juxtaposed to the neutral fixed contactor 90, and the other ground side connection terminal is provided via the ground side connection conductor 24a.
Electrically connected to 4.

The neutral movable contacts 92, 92 (movable contacts) are composed of one piece 92A, 92A which contacts and separates the first neutral fixed contact 90 and another piece 92B which separates and contacts the second neutral fixed contact 91. 92B and one of these pieces 92A, 92A and the other piece
The connecting pieces 92C and 92C connecting the 92B and 92B are formed in a substantially U-shape. On the other hand, the pieces 92A, 92A have spring receiving portions 92a, 92a for mounting the contact spring 93 on the center back surface thereof, and the contact spring 93 can be mounted between the body 12 and the contact spring 93. The one-sided pieces 92A, 92A have movable contact portions 92b, 92b on the inner surface of the tip thereof, and can be brought into contact with and separated from the first neutral fixed contact 90 by facing the first neutral fixed contact 90. The other piece 92B, 92B has its tip 92
A contact portion of a neutral handle 94 (operation handle), which will be described later, comes into contact with c and 92c, and the neutral movable contact 92, 92 is moved by rotating the neutral handle 94 (operation handle). It can be attached to and detached from 91. The other pieces 92B, 92B also have movable contact portions 92d, 92B on the outer surface of the base end thereof.
By having d and facing the second neutral fixed contact 91, the second neutral fixed contact 91 can be brought into and out of contact with the second neutral fixed contact 91. In other words, the neutral handle 94 (operation handle) is connected to the neutral movable contacts 92, 92 (movable contacts).
The other piece 92B, 92B of the other piece 92B, 92B
B When operated to rotate toward the base end, the neutral movable contact
The tips of the one piece 92A, 92A of 92, 92 rotate in the same direction as the direction in which the neutral handle 94 rotates about the base end of the other piece 92B, 92B, and move away from the first neutral fixed contact 90, so the neutral handle A small force is required to rotate 94 after contacting the tips of the other pieces 92B, 92B of the neutral movable contacts 92, 92, thereby improving the operability. Also, since the two neutral movable contacts are used to contact and separate from each neutral fixed contact, the electromagnetic repulsive force of each neutral fixed contact 90,91 and neutral movable contact 92,92 is weakened, It is possible to improve contact reliability. That is, since the electromagnetic repulsive force is proportional to the square of the electric current, when divided, the electromagnetic repulsive force becomes ¼ at 1/2 × 1/2, but since there are two places where the contact is opened, it is actually It becomes 1/4 × 2, which is 1/2 of the original.

The contact spring 93 is formed of a coil spring,
One side is the spring receiving part 92a of the neutral movable contact 92,92,
It is arranged in a state of being fitted to 92a, and the other side is in contact with the body 12.
2,92 is biased toward each neutral fixed contact 90,91. The neutral handle 94 (operation handle) is
It has a knitting cam shape and has a shaft hole 94a that is rotatably held by a bearing (not shown) of the body 12, and has an operating portion 94b and an abutting portion 94c at predetermined peripheral positions.

As shown in FIG. 11, the grounding side connecting conductor 24a is welded on one side to the other fixed contactor 91 and on the other side to the grounding side connecting terminal 4 at the other end, respectively. By operating the operation handle) to the position shown in FIG. 11, the ground side connection terminals 4 and 5 at both ends are electrically connected. Also, this ground side connecting conductor 24a is
The zero-phase current transformer 56 is inserted from the other fixed contactor 91 to be routed inside the ground-side connection conductor housing portion 21 formed in the body 12 and welded to the ground-side connection terminal 4 at the other end. By being arranged in the connection conductor housing portion 21, it is arranged in contact with the bottom surface (mounting surface) of the body 12, and heat generated in the ground-side connection conductor 24a when attached to a distribution board or the like is prevented. It is easy to radiate heat to the outside, so that the operation of each member (particularly bimetal) inside the body 12 is less likely to be hindered. In this neutral device 24, when the operation portion 94b of the neutral handle 94 (operation handle) is set in the vertical direction, as shown in FIG.
The abutting portion 94c does not abut the neutral movable contactor 92, and the spring force of the contact spring 93 causes the movable contact portion 92b of the one side piece 92A.
Comes into contact with the fixed contact 90, and the movable contact 92d of the other piece 92B comes into contact with the other fixed contact 91, so that the ground side connection terminals 4 and 5 at both ends of the body 12 are brought into conduction. From this state, when the operation portion 94b of the neutral handle 94 (operation handle) is rotated in the horizontal direction, the contact portion 94c of the neutral handle 94 (operation handle) comes into contact with the tip 92c of the other piece 92B. When the rotating operation is further continued, one piece 92A of the neutral movable contact 92 is separated from the fixed contact 90, and the other piece 92B of the neutral movable contact 92 is separated from the other fixed contact 91. At this time, the neutral handle 94 (operation handle) is connected to the neutral movable contact 92 by the contact spring.
Frictionally locked with 93 compressed.

[0043]

According to the neutral device of the circuit breaker of the present invention, the current flowing from one fixed contact is divided into two movable contacts and flows to the other fixed contact.
The electromagnetic repulsive force of each contact is weakened, and contact reliability is improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a circuit breaker to which the present invention is applied.

FIG. 2 is an exploded perspective view showing the assembled state of FIG.

FIG. 3 is a front view showing the state of FIG. 1 with the first cover removed.

FIG. 4 is a perspective view showing a state where the thing of FIG. 1 is assembled.

5 is a side view of the neutral device side of FIG. 4; FIG.

FIG. 6 is a top view of that of FIG.

FIG. 7 is a side view of the side of the neutral device side of FIG. 4;

FIG. 8 is a front view showing the ON state of the one shown in FIG. 3;

9 is a front view showing the tripped state of the one shown in FIG. 3; FIG.

FIG. 10 is a diagram for explaining a trip operation due to electric leakage, and is a front view showing a state where the first cover of FIG. 4 is removed.

FIG. 11 is a back view showing the state of FIG. 4 with the second cover removed.

12 is a perspective view showing the neutral movable contact (movable contact) of FIG. 11. FIG.

[Explanation of symbols]

 24 Neutral device 90 1st neutral fixed contactor (fixed contactor) 91 2nd neutral fixed contactor (fixed contactor) 92,92 Neutral movable contactor (movable contactor) 92A, 92A One piece 92B, 92B Another piece 92C , 92C Coupling piece 93 Contact spring 94 Neutral handle (operation handle)

Claims (1)

[Claims] 1. Two fixed contacts arranged side by side, one fixed contact is brought into contact with and separated from the inner surface of the tip of one piece, and the other fixed contact is provided on the outer surface of the base end of the other piece facing the one piece. Two movable contactors each formed in a substantially U-shape by the contacting / separating connecting piece, a single contact spring biasing one of the two movable contactors toward the other, and two movable contactors. A neutral device for a circuit breaker, comprising: a single operation handle that abuts on the other end of the contact to bring it into and out of contact with each fixed contact.